Safety shoes designed to protect feet from common hazards such as falling or rolling objects, cuts and punctures are well known. Such shoes are required personal protective equipment for many occupations. According to the Occupational Safety and Health Administration (OSHA), safety shoes should be sturdy and have an impact resistant toe. Often the entire toe box and insole are reinforced with steel. Sometimes the instep is protected by steel, aluminum or plastic materials. Safety shoes are also usually equipped with special soles to guard against slip, chemical, and/or electrical hazards. Thus, safety shoes and boots protect the feet, help prevent injuries to them, and reduce the severity of injuries that do occur in the workplace. Yet, only one out of every four victims of a job-related foot injury were wearing any type of safety shoes or boot. The most common reason for this is that workers often complain about the comfort and/or style of the safety shoes available. The present invention addresses these problems by providing a safety shoe which is comfortable, flexible, stylish, and still provides protection from injury. This surprising result is accomplished through the application of stitch-down shoe construction to safety shoe technology.
Stitch-down construction for shoes in general has long been known, as illustrated, for example, in U.S. Pat. No. 2,123,278 which issued in 1938. However, it has not been accepted in the safety shoe industry because of the difficulty of trying to include a steel toe box into the constructions.
Moccasin type safety shoes have been described in U.S. Pat. Nos. 4,451,949 and 4,566,197. While these shoes have a casual style, this type of shoe often does not have the sturdiness and long life required in safety shoes.
Welt type construction for shoes is generally considered to be very strong. Welt shoes are also generally favoured because they can be easily resoled. A problem encountered when trying to make welt type safety shoes is the fact that the steel toe box generally has inwardly extending flanges which are normally at least 3/16 inch. These flanges are necessary to distribute forces applied to the top of the toe box sufficiently to comply with OSHA regulations relating to the acceptable amount of depression of the toe box in response to various tests. Canadian Patent 1,110,060 and U.S. Pat. No. 3,034,235 provide a groove in the mid-sole to accommodate the flanges and therefore reduce the profile of the steel toe box for easier welting. However, this adds to the cost of manufacture and the reduced profile of the toe means that these shoes will not pass the most rigorous OSHA depression requirements.
Another type of safety shoe incorporating a typical welt type of construction is disclosed in U.S. Pat. No. 4,011,667. As can be gathered from this U.S. patent, welt type safety shoes are difficult to manufacture and result in a very bulky joint around the edges. While welt type shoes are generally considered to be of sturdy construction, they also have the disadvantages that they are heavy, inflexible and generally conservative in style, thus contributing to the problem that workers do not always wear the personal protective equipment available to them. The present invention addresses this problem through the surprisingly result that OSHA compliant safety shoes which are lightweight, flexible and stylish can be manufactured using stitch-down construction.